In order to facilitate maintenance and management services, there is a display apparatus that superimposes a plurality of image data items to generate one still image (for example, Japanese Laid-open Patent Publication No. 2001-14316). The display apparatus evaluates an absolute position of each image and relative positions between the plurality of image data items while generating a still image so as to correspond the position of each other. After a video camera is directed in a predetermined direction, an automobile having the video camera mounted therein runs along an object, thereby collecting a plurality of image data items. In maintenance and management services for a building, a road, a bridge, and the like, the display apparatus is intended to manage structures, such as a bridge through a road, a slope, and the like, as one still image.